Semiconductor devices have dramatically decreased in size in recent years. Some modern devices include features that are less than 100 nanometers in size, e.g., 45 nanometers and/or 32 nanometers. As device and feature sizes continue to shrink, processing methods and materials need to be improved.
Titanium nitride has various applications in the semiconductor industry, such as hard masks, metal barriers, conductive electrodes, metal gates, and many others. Its widespread use is attributed in part by good metal diffusion blocking characteristics and low resistivity of about 30-70 micro Ohm-cm after annealing. Some new 45 nanometer chip configurations and beyond make use of titanium nitride for improved transistor performance. Titanium nitride structures may be provided on the same substrate with aluminum structures that may be used as work function materials and/or contacts.